Direction signal



Oct. 14, 1941. H. c. DOANE 2,258,747

DIRECTION SIGNAL Filed March 2, 1939 SWITCH M Z I Snmmo:

Patented a. 1 4, 1941 DIRECTION SIGNAL Harry 0. Doane, Flint, Mlch., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application March 2, 1939, Serial No. 259,421

1 Claim.

This invention has to do with improvements in direction signals such as are used on automobiles.

In such systems it is customary toprovide signal lights on opposite sides of the car and to flash the light or, lights on the side toward which the turn is to be made. For operating the signal it is customary to provide a switch at a point convenient to the operator and to provide some indicating means to apprise the driver that the signal is on so that there is less likelihood of its being left on unintentionally when no turn is being made and so that the driver may know whether or not it is in working order.

This invention has to do, among other things, with an indicator for such systems operating through the sense of touch and also preferably through the sense of hearing. This may be simply accomplished by mounting on the dash in position to transmit its vibrations to the steering column a flashercapable of producing a slight amount of vibration as well as the desired interruption of the circuit. Accompanying the vibration is a slight clicking nois providing further indication of the operation of the system. There is also preferably employed a pilot so arranged as to be flashed by the operation of the flasher;

Other features of the invention will be pointed out in the course of the following description-in which:

Figure 1 is a perspective view showing the mounting of the direction signal switchand the flasher.

Figure 2 is a diagrammatic view of the direction signal circuit showing details of the flasher.

Referring first to Figure 2, B indicates the usual battery from which current is supplied through the usual ignition switch and a suitable fuse to the terminal 10 of flasher i2. The terminal I0 is mounted on insulator H. The flasher is of the well known thermal type here shown as consisting of a metal stamping l4 secured to insulator II by terminal 30 and carrying insulated coil 15 having one end connected to terminal Ill. The other end of the coil is secured to U-shaped contact l8 supported by insulator l9 mounted on stamping H. To the contact I8 is secured a resistance wire 20, the other end of which is secured to a heat responsive element consisting of a longitudinally expansible resistance wire 22 anchored in insulating bead 26 secured to bracket 28 mounted on stamping l4. The other end of heat responsive element 22 is secured to the free end of resilient armature 24 mounted on the tion with stamping I2, is connected to movable switch member 32 having contacts'L and R in circuit with left signal lamp L and right signal lamp R respectively. A pilot light is con- 'ture 24, stamping N, terminal 30 and switch 32 to the left hand signal lamp. However, the

amount of current flowing in the circuit is small due to the high resistance of the elements 20 and 22. Because of this high resistance the pilot light burns brightly since it is subjected to the relatively high voltage existing across the terminals of the flasher. The current flowing through the flasher causes the heat responsive element 22 to expand until armature 24 engages contact I8 thereby short-circuiting the elements 20 and 22.

The result of this is to allow increased flow of current to the left signal light L causing it to burn brightly. At the same time the reduced voltage acrossth terminals I0 and 30 of the interrupter causes the pilot light to go out for lack of suiflcient voltage. During the period that the armature 24 engages contact Hi the flow of current through coil I6 is so great as to cause it to attract the armature 24 with considerable force.

With the elements 20 and 22 short-circuited the flow of current through them is greatly reduced and the element 22 cools and contracts and soon exerts sufllcient force to overcome the pull of the magnet I6 and break the engagement between armature 24 and contact 18, thus restoringthe parts to their initial position.

In the manner described the signal light L and the pilotlight are alternatively lighted and ex-' tinguished as the flasher goes through its cycle. The action of the flasher produces a clicking noise and a small amount of vibration.

To indicat a right turn it is but necessary to swing the switch 32 so it engages terminal R. When the switch is in mid-position no signal is given. At this time, of course, the pilot light is out and the flasher is not functioning. Should the switch 32 be turned to either signaling position the pilot light will, of course, flash and the interrupter will click and vibrate, but should the signal light filament burnout the flasher will no longer operate, nor will the pilot light, since all current supplied to them must go through the signal light bulb.

stamping l4. Terminal 30, in conducting rela- In Figure 1 the mounting of the parts of the signaling system is shown in some detail. The

flasher I2 is mounted on the rear oi the dash 42 adjacent the point where the steering column bracket 44 is secured to the dash. At the upper end or the steering column 40 is mounted the usual steering wheel 48, the shaft oi which (not shown) is mounted in bearings inside the steering column. With this arrangement the vibration resulting from operation of the flasher i2 is transmitted through the steering column bracket 44 and steering column 4 to the steering wheel 48 and as the operator always has his hands on the steering wheel he is bound to feel the vibration from the flasher as long as the signal light is on.

. There is also mounted on the steering column 48 a bracket 50 in which is journaled one end of a rockshaft 52 to which is secured an operating lever 54 for shifting the gears of the transmission. The direction signal switch 32 is mounted on the underside of the operating lever 54 with 20 parentcover over the pilot light. With this arrangement it is hardly likely that the driver will be unaware that his directionsignal is on for his attention is called to it by the vibration previously described. by the clicking oi the circuit breaker l2 and by the flashing oi the pilot light. A glance at the handle ll of the switch I! tells him whether or not the signal has been left on.

Various modifications will occur to those skilled in the art.

I claim:

The combination with an instrument panel, a steering wheel column having a rigid connection with the panel and a gear control handle mounted on the column, of a direction signal system comprising an electrically actuated signal, a con trol switch mounted on said handle. and a vibration producing interrupter and audible signal device incorporated in the signal system between the signal and switch and means mounting said devic on the instrument panel'for the transmission of vibrations produced thereby through the panel and into the steering wheel column.

HARRY C. DOAN E. 

